A dust model for the cosmic microwave background

Wickramasinghe, N. C.; Edmunds, M. G.; Chitre, S. M.; Narlikar, Jayant V.; Ramadurai, S.

doi:10.1007/bf00644839

Cited by 22 publications

(11 citation statements)

References 16 publications

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“…As shown in Figure 2, Dwek (2004) argued that, combined with the silicate-graphite mixture for the R V = 3.1 model (Zubko et al 2004), metallic needles 9 with a typical length (l) over radius (a) ratio of l/a ≈ 600 and a needle-to-H mass ratio of ∼ 5 × 10 −6 could explain the flat mid-IR extinction derived by Lutz (1999) 8 The carbonaceous grain population was assumed to extend from grains with graphitic properties at radii a > 0.01 µm, down to particles with PAH-like properties at very small sizes (see Li & Draine 2001). 9 The idea of metallic needles was originally brought up by Hoyle et al (1968) and Wickramasinghe et al (1975) to explain the 2.7 K cosmic microwave background (CMB). They argued that the 2.7 K CMB might have arisen from the radiation of "Population III" objects thermalized by long slender conducting cosmic whiskers or "cosmic needles".…”

Section: Modeling the Mid-ir Extinction: Where Do We Stand?mentioning

confidence: 99%

Modeling the infrared interstellar extinction

Wang

Jiang

2014

Planetary and Space Science

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How dust scatters and absorbs starlight in the interstellar medium (ISM) contains important clues about the size and composition of interstellar dust. While the ultraviolet (UV) and visible interstellar extinction is well studied and can be closely fitted in terms of various dust mixtures (e.g., the silicategraphite mixture), the infrared (IR) extinction is not well understood, particularly, the mid-IR extinction in the 3-8 µm wavelength range is rather flat (or "gray") and is inconsistent with the standard Mathis, Rumpl, & Nordsieck (MRN) silicate-graphite dust model. We attempt to reproduce the flat IR extinction by exploring various dust sizes and species, including amorphous silicate, graphite, amorphous carbon and iron. We find that the flat IR extinction is best explained in terms of micrometer-sized amorphous carbon dust which consumes ∼60 carbon atoms per million hydrogen atoms (i.e., C/H ≈ 60 ppm). To account for the observed UV/visible and near-IR extinction, the silicate-graphite model requires Si/H ≈ 34 ppm and C/H ≈ 292 ppm. We conclude that the extinction from the UV to the mid-IR could be closely reproduced by a mixture of submicrometer-sized amorphous silicate dust, submicrometer-sized graphitic dust, and micrometer-sized amorphous carbon dust, at the expense of excess C available in the ISM (i.e., this model requires a solid-phase C abundance of C/H ≈ 352 ppm, considerably exceeding what could be available in the ISM).

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Section: Modeling the Mid-ir Extinction: Where Do We Stand?mentioning

confidence: 99%

Modeling the infrared interstellar extinction

Wang

Jiang

2014

Planetary and Space Science

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“…The reason why is because the reaction violates the conservation of baryon numbers. At least two authors (Sakharov 1967;Wilczek 1980) have already argued that a violation of the conservation of elementary baryon numbers is actually needed to explain the observed baryon asymmetry between matter and antimatter in the real universe.…”

Section: Final Remarksmentioning

confidence: 98%

“…Aguirre (1999) appeals to the possible existence of grey intergalactic dust as the primary cause for this dimming. The grey intergalactic dust might exist in the form of solid carbon-rich needles first proposed by Wickramasinghe et al (1975). This needle type dust might originate from starburst galaxies undergoing expulsion of both gas and dust (cf.…”

Section: Final Remarksmentioning

confidence: 99%

The cosmic age crisis and the Hubble constant in a non-expanding universe

Sorrell

2008

Astrophys Space Sci

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The present paper outlines a cosmological paradigm based upon Dirac's large number hypothesis and continual creation of matter in a closed static (nonexpanding) universe. The cosmological redshift is caused by the tired-light phenomenon originally proposed by Zwicky. It is shown that the tired-light cosmology together with continual matter creation has a universal Hubble constant H 0 = (512π 2 /3) 1/6 (GC 0 ) 1/3 fixed by the universal rate C 0 of matter creation, where G is Newton's gravitational constant. It is also shown that a closed static universe has a finite age τ 0 = (243π 5 /8GC 0 ) 1/3 also fixed by the universal rate of matter creation. The invariant relationship H 0 τ 0 = 3π 2 6 1/2 shows that a closed static universe is much older (≈ one trillion years) than any expanding universe model based upon Big-Bang cosmology. It is this property of a static universe that resolves any cosmic age crisis provided that galaxy formation in the universe is a continual recurring process. Application of Dirac's large number hypothesis gives a matter creation rate C 0 = 4.6×10 −48 gm cm −3 s −1 depending only on the fundamental constants of nature. Hence, the model shows that a closed static universe has a Hubble constant H 0 = 70 km s −1 Mpc −1 in good agreement with recent astronomical determinations of H 0 . By using the above numerical value for H 0 together with observational data for elongated cellular-wall structures containing superclusters of galaxies, it is shown that the elongated cellular-wall configurations observed in the real universe are at least one hundred billion years old.

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“…Modeled as emission from normal dust, this radiation implies very high dust masses, possibly inconsistent with the age of the objects and their expected heavyelement evolution (Wickramasinghe et al 1995 ;McMahon et al 1994 ;Eales & Edmunds 1996). The masses required in whiskers would be much lower.…”

Section: Evidence For Whiskersmentioning

confidence: 99%

“…The caveat to this conclusion, however, is that the long-wavelength (j Z 100 km) opacity of intergalactic dust is almost completely unconstrained ; a population of dust with properties that lead to high opacity at long wavelengths might provide the necessary optical depth. Such grain types include hollow spheres (Layzer & Hively 1973), whiskers (e.g., Wickramasinghe et al 1975 ;Wright 1982 ;Hawkins & Wright 1988 ;Hoyle & Wickramasinghe 1988), and "" Ñu †y ÏÏ or fractal grains (e.g., Wright 1987 ;Stogniento et al 1995). The very accurately thermal spectrum of the CMB does not, therefore, by itself rule out the CBB ; rather, one must compare speciÐc CBB thermalization models with the available data and determine which modelsÈif anyÈare viable.…”

Section: Introductionmentioning

confidence: 99%

Untitled

2000

ApJ

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In the context of a cold big bang (CBB) cosmological model, I estimate the temperature, calculate the evolution, and discuss the anisotropies of a homogeneous radiation background emitted at high redshift by Population III objects and thermalized by a mixture of carbon/silicate dust and iron or carbon whiskers. Assuming that Population III objects supply dark matter remnants and produce the universal helium abundance of D24%, the resulting radiation, if thermal, should have temperature 0.5 K [ T 0 [ 9 K. To calculate its thermalization I limit standard dust density using constraints from maximum allowed metallicity, quasar reddening, Type Ia supernova observations, and high-redshift object visibility and assume a small mass ratio of whiskers to standard dust. For high redshift of generation (z i Z 100) and highly conducting, high aspect ratio (length/diameter iron whiskers, the Ðnal spectrum meets Z1000) the FIRAS spectral distortion limits and does not exceed limits on IR-background light. Energetic considerations probably require if the observed cosmic microwave background (CMB) is star genz i [ 40) b erated. Such a model is marginally viable with baryon density but probably ruled out if5. I comment brieÑy on possible other thermalization mechanisms. In whisker-thermalized models, CMB anisotropies are imprinted at lower redshift and through somewhat di †erent physical processes than in the hot big bang (HBB). Nonlocal thermal equilibrium of the dust causes the Sachs-Wolfe e †ect to disappear on small angular scales. Radiation pressure probably ejects whiskers from luminous regions such as galaxies. If signiÐcant intergalactic magnetic Ðelds are absent, CMB radiation drag probably Ðxes whiskers in the CMB frame, hence large-scale Doppler anisotropies (other than the dipole) do not exist. "" Intrinsic ÏÏ temperature Ñuctuations and the integrated Sachs-Wolfe e †ect operate essentially as in the HBB. Numerical results for the horizon, di †usion, and other length scales relevant to CMB anisotropies for Ðducial thermalization models are provided. Finally, I note that CMB polarization may be higher in the whisker model than in the HBB and that acoustic oscillations should not appear in the CBB power spectrum, and I comment on the amplitude and possible frequency dependence of the anisotropies.

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A dust model for the cosmic microwave background

Cited by 22 publications

References 16 publications

Modeling the infrared interstellar extinction

Modeling the infrared interstellar extinction

The cosmic age crisis and the Hubble constant in a non-expanding universe

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